To create these works of art all you need to do is to push a relatively long turd, but before you cut the turtle, you need to stand up straight and mash your bum cheeks together.
This traps the turd between your bum cheeks and forms symmetrical Wing like shapes on both sides.

To see your work of art all you do is bend over in front of a mirror, spread your cheeks and enjoy your art!!

Son - Hey mom, you should have seen the beautiful butterfly i made at school today.
Mom - oh thats nice, why didn't you bring it home to show me?
Son - because all the other kids complained that i stink too much!!!
Mom - What do you mean?
Son - Its BUM-ART mom.